Terry Doyle writes …
In 1999, a seminal paper appeared in the medical literature entitled ‘Tamoxifen Prevention of Breast Cancer: an Instance of the Fingerpost’ (Scott M. Lippman and Powel H. Brown. J. Natl. Cancer Inst. (1999) 91 (21): 1809–19). After analyzing the results of a large trial, the authors discussed the value of the oestrogen antagonist drug Tamoxifen in reducing the growth of breast cancers, calling it ‘an instance of the fingerpost for resolving the intense debate on the future direction of chemoprevention research’.
The first use of the term ‘an instance of the fingerpost’ was by Francis Bacon in his Novum Organum (II, Aphorism 36) referring to a scientific test ‘borrowing the term from the fingerposts which are set up where roads part, to indicate the several directions’. It is one of the Prerogative Instances, which he cites in describing his inductive method, where an investigator must make a correct choice of direction between ideas the initial evidence for which is ‘so balanced as to be uncertain’.
These and other Baconian ideas are explored in An Instance of the Fingerpost by Oxford art historian Iain Pears, where mid-1660s Oxford is used as a microcosm for the intellectual, religious and political turmoil of the period just after the Restoration of Charles II. The aporias of the novel centre on the mysterious death of Robert Grove, a Fellow of New College. Explanations of his death are given by four witnesses. The first is a Venetian Catholic intent on claiming precedence over Richard Lower as the first blood transfusionist. The second is the son of a supposed traitor to the Royalist cause intent on vindicating his father. The third is John Wallis (1616–1703), mathematician and cryptographer to both Cromwell and Charles II. The fourth is Anthony Wood the Oxford antiquarian (1632–1695). The Dramatis Personae include famous virtuosi from the period; John Aubrey, Robert Boyle, John Locke, Richard Lower, the German chymist Peter Stahl and Christopher Wren.
The intellectual backbone of the novel is Francis Bacon’s discussion of inductive reasoning in Novum Organum (1620), where he points out the fallacies that may beset logical thinking. Each of the four sections of Pears’ novel is preceded by an epigraph from Bacon’s work. The first are three of his four ‘Idols of the Mind’ –– ‘The Idols of the Market’ (referring to a misuse of language); ‘The Idols of the Cavern’ (meaning personal obsessions); ‘The Idols of the Theatre’ (the danger of false reasoning). The fourth section is entitled ‘An Instance of the Fingerpost’ and the epigraph is an abridged version of the original.
When in a Search of any Nature the Understanding stands suspended, then Instances of the Fingerpost shew the true and inviolable Way in which the Question is to be decided. These Instances afford great Light, so that the Course of the Investigations will sometimes be terminated by them. Sometimes, indeed, these Instances are found amongst that Evidence already set down. Aphorism 36.
Among other interesting matters considered in the novel is the theory of fevers; ‘Could a loss of blood mean that there is insufficient to vent the excess heat from the heart?’ (p. 58) and Sylvius’ theory of the life spirit. ‘You have fallen under the influence of Monsieur Descartes’, says Richard Lower . . . ‘you have constructed a theory, and that leads you to recommend a practice. You have no evidence that it would work . . . The alternative, proposed by my Lord Bacon, is to amass evidence, and then to frame an explanation which takes into account all that is known’. (Iain Pears, An Instance of the Fingerpost. New York: Riverhead Books, 1998, p. 59–60)
The authors of the Tamoxifen paper acknowledge in their title that they rely for their conclusions on Bacon’s notion of eliminative induction. This was the means by which they established that the growth of oestrogen receptor positive breast cancers is halted by the drug Tamoxifen. So Sir Francis’ work turns out to be pretty useful. Little wonder that the late great Bacon scholar Graham Rees regarded the passage in which Bacon discusses instances of the fingerpost as ‘a startlingly original expression of a central aspect of the theory of experiment’.